The UK has stood by its assessment of the threat posed by the Beta variant of coronavirus in France despite mounting criticism from scientific experts from both sides of the Channel.
Boris Johnson’s government said its decision to maintain a 10-day quarantine for travellers from France while relaxing the restriction for other EU countries was based on the “persistent presence of cases in France” of the variant that first emerged in South Africa. The rule means that even people who have been fully vaccinated will have to quarantine when travelling from France, unlike those coming from other places like Spain, Portugal, or Greece.
The reasoning has been met with bafflement by scientists who point out that the Beta variant has been falling in prevalence in France as the more contagious Delta variant has taken over.
But on Wednesday, the UK said data from Gisaid, a platform where countries upload their Covid-19 viral sequences, showed that France had registered a total of 2,959 cases of the Beta variant to date, or 5.2 per cent of all cases — almost triple that of the UK. It also noted that there were more cases of the Beta variant uploaded to Gisaid in the past three or four months in France, than Spain or Greece.
“France has the second highest percentage of Beta cases in the world, following South Africa,” The Department of Health and Social Care said.
However this assessment differs from data from Sante Publique France, that estimates the Beta strain is now at 2.8 per cent of cases in mainland France, down from 7 per cent two months ago.
But scientists even contested the reading of the Gisaid data by the UK government. Florence Débarre, a biologist at France’s state-owned National Centre for Scientific Research who has access to the entire Gisaid database, suggested there were at least a dozen countries with higher proportions of Beta than France whether looking at trends from the start of the pandemic, the start of May, or the start of April.
According to publicly available data from Gisaid, 3.7 per cent of cases in France were due to the Beta variant in the past four weeks, compared with 6.9 per cent in Spain.
There appeared to be “no reason to believe [Beta] would be more competitive than the Delta variant or would establish itself in the UK,” said Sylvie van der Werf, a molecular geneticist at the Institut Pasteur, adding she was “puzzled” by the UK’s decision.
“The only reason — and it’s questionable still — is the variant’s higher immune escape,” she added. She was referring to findings suggesting that the Beta variant is more vaccine resistant than others in circulation, especially to the AstraZeneca vaccine, widely used in the UK.
Some experts questioned whether the UK authorities could have confused the prevalence of Beta in mainland France and its overseas territories, which include the islands of Martinique and Guadeloupe in the Caribbean, and Réunion in the Indian Ocean. The latter has much higher Beta prevalence, estimated to be more than 90 per cent of cases currently.
But the UK government confirmed on Wednesday that its decision was based exclusively on data from mainland France.
Ravi Gupta, Cambridge university professor who is a member of a government advisory group that analyses Covid-19 variants, also pointed out that the measures regarding France were imposed as the UK lifted most remaining restrictions on life and business against the advice of global health experts.
The policy “is poorly thought out and it hasn’t used the best available knowledge and common sense”, said Gupta. “If we had continued with mitigation measures in the UK, I would understand taking such a precautionary approach.”